1. Field of the Invention
The present invention provides a safety mechanism useful in warhead fuses that sufficiently restricts the alignment of the booster lead and the warhead detonator to preclude transfer of an explosive event through the booster lead thereby preventing accidental detonation of the warhead main charge.
2. Related Art
Typically, conventional explosive trains include a fuze, detonator, safe/arm mechanism, booster charge, and explosive device or warhead. Current fuses such as those incorporated in general purpose bombs used by the military contain a pellet of booster explosive to initiate the main charge explosive. The fuse pellet may be made from a primary explosive to allow a slapper or detonator to initiate the booster pellet. However, the primary explosive may be subject to an accidental detonation, such as high-speed fragment impact, cook off, or other initiating occurrence resulting from shipboard accidents or operations, mishandling, etc. With accidental detonation, the primary explosive is likely to detonate the main charge explosive. One example of a munition that suffers from the problem of accidental armed deployment is the M230/M231 fuze used on the sub-munitions of the 2.75 multi-purpose sub-munition (MPSM) Rocket Warhead. This munition contains a spring loaded (stored energy) firing pin, which can cause unintentional or accidental detonation of armed dud sub-munitions, such as the M73/M75, on the battlefield or upon accidental expulsion. Accidental explosion of sub-munitions on board warships or other installations present potentially serious safety hazards to personnel, equipment and expensive weapon systems.
Safe/arm mechanisms are interposed between the detonator and booster to protect the explosive device from accidental detonation. The safe/arm mechanisms may include out-of-line methodologies whereby the detonator is separated from the booster by one or more physical barriers. Accidental detonation of the detonator can not penetrate the physical barrier and detonate the warhead. Although this method is simple and direct, it may not always prove reliable.
The military has fielded main charge explosives such as PBXN-113 and AFX-757 that are qualified as Extremely Insensitive Detonating Substances (EIDS) or 1.6S materials. EIDS materials offer less susceptibility to stimuli such as fragment attack and cook off. A warhead having a detonator, fuse, and main charge explosive meeting the 1.6 standard need fuses that are less vulnerable to fragment attack and thermal cook off.
There is a need in the art to provide improved safety of fuse mechanisms for explosives. The present invention addresses this and other needs.